If you don’t already know, GRUB 2.00 is the default grub on Linux Mint 14 (Nadia). It's more advanced and gives you a cleaner grub menu with fewer entries.

If you wish to upgrade your Mint, then follow this tutorial:1-What's GRUB?

GRUB (GRand Unified Bootloader) is the program that helps boot up your computer when you turn it on. Without it, you wouldn’t be able to load Linux Mint. So, it’s very important that you know what do to in case something goes wrong before upgrading it. The least make will render your computer inoperable.

2- Installation:

I-To install from PPA:

In this tutorial we will see how to upgrade/install GRUB 2.00 from PPA on a system running Ubuntu 12.04 (Precise Pangolin) and Linux Mint 13. Installing from PPA will be easier than installing manually from source because you may get unresolved errors. This latest version brings more improvements, bug fixes and corrections. Installation